a = 10
b = 20

# 1、方法一：利用中间变量
c = a
a = b
b = c
print(f'a = {a}')
print(f'b = {b}')
print('============')

# 2、方法二
a, b = b, a
print(f'a = {a}')
print(f'b = {b}')
print('============')
